Brother Z-8550A Service Manual page 75

Turning the stitch length dial (1) to a setting greater than 2.5
In this case, replace gauge parts such as the feed dog with parts for using with a feed amount of more than 2.0 mm.
In addition, change the maximum feed amount setting while referring to page 64, and then adjust the stitch length dial (1) as
described below.
8. CHANGING THE FEED AMOUNT TO LONG STITCH SPECIFICATIONS (from 2.0mm to 5.0mm)
Setting for 1st turn
Setting for 2nd turn
9. For sewing machine models and specifications other than
8550A-031, push the reverse stitching lever (9) down all
the way (so that the plunger (11) of the quick reverse
solenoid has moved to its highest position), and then
tighten the two screws (1) at the position where the quick
reverse solenoid (2) is touching to top of section (A) of
the plunger (11).
3505M
1. Turn the stitch length dial (1) all the way to "2.5".
2. After this, push the left lever (2) while turning the stitch
length dial (1) so that it can be turned a second time.
When the stitch length dial (1) is turned a second time,
the settings will be those on the inside of the scale (3−5).
* When turning the dial from a larger number to a smaller
number, it can be turned to the second time setting
without pushing the left lever (2).
1164B
Z-8550A, 8560A
66